'05 Screech on Cold Start - Toyota 4Runner Forum

WRTR5 · 12-09-2020, 12:21 AM

Ok so I'm probably being a baby but this screech on cold start is concerning me. I'm guessing it has something to do with the power steering pump?

2005 4Runner Screech on Cold Start - YouTube

royal T4R · 12-09-2020, 01:43 PM

V6 or V8

It sounds like an electric pump, not mechanical. My V8 also makes a noise similar to that just not as violent. I believe it has something to do with the brake booster.

AuSeeker · 12-09-2020, 08:04 PM

Quote:

Originally Posted by WRTR5

Ok so I'm probably being a baby but this screech on cold start is concerning me. I'm guessing it has something to do with the power steering pump?

2005 4Runner Screech on Cold Start - YouTube

Quote:

Originally Posted by royal T4R

V6 or V8

It sounds like an electric pump, not mechanical. My V8 also makes a noise similar to that just not as violent. I believe it has something to do with the brake booster.

I also think it's most likely the electric ABS/booster pump motor making the noise, if it is the motor it should also make the noise when you use the brakes several times, normal operation is the motor comes on when you turn on the ignition and also comes on after you depress the brake pedal approximately 3 to 4 times as the pressure drops, the motor normally runs about 10 to 15 seconds or so the motor should only make a slight buzzing noise but if the brushes are worn down it will be much more noisier like the noise you're is making.

You need to pinpoint where the noise is coming from, if in the area of the master cylinder, then I would check the motor.

WRTR5 · 12-09-2020, 09:27 PM

Quote:

Originally Posted by AuSeeker

I also think it's most likely the electric ABS/booster pump motor making the noise, if it is the motor it should also make the noise when you use the brakes several times, normal operation is the motor comes on when you turn on the ignition and also comes on after you depress the brake pedal approximately 3 to 4 times as the pressure drops, the motor normally runs about 10 to 15 seconds or so the motor should only make a slight buzzing noise but if the brushes are worn down it will be much more noisier like the noise you're is making.

You need to pinpoint where the noise is coming from, if in the area of the master cylinder, then I would check the motor.

It only occurs on a cold start and doesn't happen anytime after that. Even if I rapidly tap the brakes it doesn't make the sound. Also, the engine has to be cold. If the temps outside are like 60 F it doesn't do it which is strange.

WRTR5 · 12-09-2020, 09:28 PM

Quote:

Originally Posted by royal T4R

V6 or V8

It sounds like an electric pump, not mechanical. My V8 also makes a noise similar to that just not as violent. I believe it has something to do with the brake booster.

Its a V6

AuSeeker · 12-09-2020, 09:49 PM

Quote:

Originally Posted by WRTR5

It only occurs on a cold start and doesn't happen anytime after that. Even if I rapidly tap the brakes it doesn't make the sound. Also, the engine has to be cold. If the temps outside are like 60 F it doesn't do it which is strange.

You are still going to have to pinpoint where this sound is coming from before you can find what it is that's making the noise, from the sound I heard in your video I'm still thinking it's the electric ABS/booster motor, it could only be making the noise when cold and then heat buildup could possibly cause the noise to cease, pinpoint where it's coming from and then we can possibly determine what causing it.

WRTR5 · 12-09-2020, 11:58 PM

Quote:

Originally Posted by AuSeeker

You are still going to have to pinpoint where this sound is coming from before you can find what it is that's making the noise, from the sound I heard in your video I'm still thinking it's the electric ABS/booster motor, it could only be making the noise when cold and then heat buildup could possibly cause the noise to cease, pinpoint where it's coming from and then we can possibly determine what causing it.

alright well I'll have to wait till the weather's cold enough then I'll try to pinpoint it. Thanks for the help!

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